Quantitative assessment methods are critical to virtually all intellectual and developmental disabilities research programs that evaluate psychosocial, behavioral or biological processes. Given the KIDDRC's emphasis on biobehavioral research, its needs take many forms, from equipment design, fabrication and maintenance, to developing and performing behavioral assessments, to creating software programs to measure social interactions. Established in 1998, the Biobehavioral Measurement Core (BMC) is the central nexus where efforts of innovative and generative core staff are channeled to meet biobehavioral research needs of KIDDRC principal invesfigators (Pls). The BMC is designed to meet the specialized needs of our four research themes. Our human translational research programs in Themes 1 and 2 are reliant on the development of software for both assessing and modifying behavior. In preclinical research conducted in Themes 3 and 4, there is a strong need for assessing rodent phenotypes associated with nervous system alterations and disruptions in eariy development. Overall, there is a need to provide sufficient support for the infrastructure so that appropriate equipment is acquired and maintained, and operations continue uninterrupted. The BMC has evolved continuously to meet new challenges in assessing behavioral and biological parameters in animal and human research.